1. Field
The present disclosure relates to a moving robot and a control method thereof, and particularly, to a moving robot capable of overcoming a wheel arrest phenomenon and a control method thereof.
2. Background
In general, robots have been developed for industrial purposes and have been in charge of part of factory automation. Recently, robot-applied fields have further extended to develop medical robots or aerospace robots, and home robots that may be used in general houses have also been made.
A typical example of a home robot is a robot cleaner, which may be a home appliance that cleans by sucking ambient dust or foreign objects, while traveling in a predetermined area. Such a robot cleaner may include a generally rechargeable battery and have an obstacle sensor capable of avoiding an obstacle during traveling so that the robot cleaner may perform cleaning while traveling.
Recently, beyond performing cleaning while robot cleaners are simply autonomously traveling in a cleaning area, research into utilization of robot cleaners in various fields such as healthcare, smart home, remote control, and the like, has been actively conducted. When a robot cleaner performs autonomous traveling in a cleaning area, the robot may meet various obstacles present in the cleaning area, and thus, an algorithm for avoiding such obstacles when performing autonomous traveling and cleaning operation may be required.
However, when a bottom surface of the cleaning area is not even, if all surface portions which are not even are recognized as obstacles, a cleaning range may be reduced, and thus, a recognition reference related to an obstacle may not be set too strictly. Thus, when the robot cleaner passes through a portion of the bottom surface without recognizing an uneven portion of the bottom surface as an obstacle, at least one of a plurality of wheels may not come into contact with the bottom surface, generating idle rotation, making it impossible for the robot cleaner to normally travel.
Also, when at least one of the plurality of wheels of the robot cleaner is completely arrested, the arrested state of the wheel may not be released only by an output from a motor. Thus, a robot cleaner that solves an idle rotation phenomenon and a complete arrest phenomenon of the wheel that may occur when the robot cleaner passes on bottom surfaces of various conditions and a control method thereof may be required. That is, a robot cleaner which may avoid the idle rotation phenomenon or complete arrest phenomenon and a control method thereof may be required.
Korean Patent Laid-Open Publication No. 10-2015-0065134 discloses a cleaning robot capable of detecting a stuck state such as a state in which the cleaning robot is caught (catching phenomenon) or lifted (lifting phenomenon) or an object stuck phenomenon, and the like, at the time of traveling. However, the related art cleaning robot may not be able to solve the catching, lifting or object-stuck phenomenon, and may require a sub-wheel installed to correspond to a main wheel and a separate motor moving the sub-wheel in the stuck state. Thus, manufacturing cost of a robot may be increased to install the sub-wheel and the motor for moving a position of the sub-wheel, and since separate electric power is required to be supplied to the separate motor to move the sub-wheel, efficiency of power consumed in the robot may be reduced.
The addition of the sub-wheel may increase a weight of the robot body, causing user inconvenience. Also, when the related art robot overpasses an obstacle, only power transmitted to the sub-wheel may be used and idle-rotation may still occur in the main wheel. The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.